Grinding device for removing cast metal projections from foundry castings

ABSTRACT

A grinding device comprising a workpiece support provided with immobilization means for the workpiece, an element for moving the workpiece towards the grinder by the rotation and/or relative translation of the support with respect to the grinder, and an element for rotating the workpiece in contact with the grinder about an axis parallel to the axis of the grinder.

United States Patent Lasserre et al.

GRINDING DEVICE FOR REMOVING CAST METAL PROJECTIONS FROM FOUNDRY CASTINGS Inventors: Roger Lasserre, St. Martin de Seignaux; Jean-Pierre Darrieussecq,,

Bassussarry, both of France Assignee: Societe Anonyme des Fonderies et Ateliers de Mousserolles, Bayonne,

France Filed: Nov. 8, 1973 Appl. No.: 413,997

Foreign Application Priority Data I Nov. 8, 1972 France 72.39520 US. Cl. 51/96; 51/105 EC; 51/234 Int. Cl. B24B 19/26 Field of Search 51/94 R, 95, 96, 97, 98,

51/124 R, 234, 105 EC, 98.5, 165.87

[ Oct. 7, 1975 [56] References Cited UNITED STATES PATENTS 2,425,234 8/1947 Erwin 51/96 3,020,681 2/1962 Hite 5l/l'24 X 3,335,527 8/1967 Sabine 5l/96 3,797,173 3/1974 Pettee 5l/98.5 X

Primary ExaminerAl Lawrence Smith Assistant Examiner-Nicholas P. Godici Attorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT A grinding device comprising a workpiece support provided with immobilization means for the workpiece, an element for moving the workpiece towards the grinder by the rotation and/or relative translation of the support with respect to the grinder, and an element for rotating the workpiece in contact with the grinder about an axis parallel to the axis of the grinder.

6 Claims, 1 Drawing Figure me -A I\IIIIIIIIIIIIIIIIIIIIIIIII 1 GRINDING DEVICE FOR REMOVING CAST METAL PROJECTIONS FROM FOUNDRY CASTINGS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for grinding off a sizeable amount of metal or similar material concentrated over a small area of a foundry casting. The

quantity of metal to be removedis disposed disymmetrically with respect to an axis of the casting. The invention relates to the removal of cast metal projections from crude foundry castings, more particularly caps for electric insulators.

2. Description of the Prior Art a I The grinding of metalfoundry castings has hitherto been effected manually. This involved considerable physical effort on the part of the person effecting the operation and caused irregular wear of the grinders. Furthermore, the quality of the grinding operation tended to vary, the amount of metal removed being either insufficient to give the casting a regular shape, or else being excessive. The grinding operation also took a fairly long time.

SUMMARY OF THE INVENTION The object of the presentinvention is to obviate the above disadvantages, to reduce the duration, of v the, grinding operation or sparking time, to permit more rational utilization and longer life of the grinders, to eliminate the physical effort required on the part of the person carrying out the operation and to improve the ground castings.

The grinding device according to the invention is characterized in that it comprises a workpiece support provided with means for immobilizing the workpiece, an element for moving the casting towards the grinder by rotation and/or relative translation of the support with respect to the grinder, an element for rotating the casting in contact with the grinder about an axis parallel to the axis of the grinder.

The grinding device according to the invention advantageously also comprises at least one of the following features: the element for moving the casting towards the grinder is a jack, one end of which is stationary with respect to the casting and the other end of which is integral with an arm supported, on the one hand, in a fixed point and, on the other, on a shaft disposed in the plane formed by the axis of the jack and by the arm, through the intermediary of means for regulating the position of the bearing point of the latter on the shaft.

The means for regulating the position of the bearing point of the arm on the shaft consist of threading provided in the latter, a threaded ring integral with the arm and screwed into the threading of the shaft and means for rotating the shaft about its axis. The fixed point of the arm is provided on the stationary axis of the support. The element which rotates the casting in contact with the grinder is a jack which preferably comprises means for regulating the rate of rotation. The above jack or jacks is/are pneumatic. The machine for grinding down cast metal projections on rough metal caps of electric insulators direct from the foundry will now be described by way of example with reference to the single FIGURE.

The crude cast metal insulator cap 1 comprisesthe cast metal projection 2 which is to be ground down by means of the grinder 3. This grinder is of a known type having a stationary spindle. In the case of a malleable cast metal cap, the grinder consists of zircon agglomerated with bakelite. The cap is rendered integral with the plate 4 which is mobile about the axis 5, by means of clamping elements "represented in diagrammatic form at 17. The centering ofthe cap on the plate is ensured by an abutment system on the head and a cone on the inner part of the cap. The plate 4 is in the rest position in the position represented at A (position for inserting-the workpiece). Once the casting has been secured to the plate, it is brought into a work position (position B of the plate 4) by means of the pneumatic jack 6 which rests, on the one hand, on the axis 7 integral withthe plate and on the axis 8 which is integral with the arm 9.'To regulate the work positionof the plate as a function of the wear of the grinder, the arm 9 is'- adapted to pivot about the axis 5. The end of the arm 9 oppositeto the axis 5 consists-of a threaded ring 10 screwed. onto the threading of 'a vertical shaft 11. The axis 5 and the shaft -11 are secured onto a casing 15. The position of the ring 10 and the shaft 11 maybe regulated by rotating the latter by means of conical gears 12 and 13. i

When the casting has been engaged by the grinder, the grinding of the cast projection is effected by progressively rotating the workpiece about an axis, represented diagrammatically at 16, according to a predetermined law so as to vary the rate of forward movement as a reverse function of the amount of metal to be removed and to keep this amount substantially constant in spite of the variations in the size of the hole in the castings. In the case of the cap shown in FIG. 1, the total angle of rotation is about 110. This angle may also be varied by varying the course of the jack 14. This enables the shape of the casting to be followed accurately owing to its elasticity. The compressed air pressure is in the order of 5 6 bars.

When the grinding operation is over, the plate is returned by the jack 6 and the cap is returned to its initial position by the jack 14. It is then removed from the plate 4 by the operator and replaced by another cap to be ground.

When the grinder has become particularly worn, for example, in the order of 5 mm, the plate support 4 is readjusted by moving the ring IlO integral with the arm 9 supporting the jack 6, by rotating the threaded shaft 11 by means of the gear 12.

Depending on the shape of the cast metal projection on the casting, various devices may be installed on the plate 4 to provide the casting with vertical translation movements, horizontal translation movements or rotation about its vertical axis.

It is also possible to use a grinder having a mobile spindle, the displacement of the plate towards the grinder then being replaced by the displacement of the grinder towards the plate.

As compared to the manual grinding of insulator caps, the above-described device makes it possible to reduce the total time of the operation by percent and the expenditure on labor and on grinders by 40 60 percent.

The grinding time itself or sparking time is reduced to 2.5 seconds. In addition, thequality of the caps is improved as the thickness of their coupling head is more constant.

When it is necessary to grind a number of different tion. The device can also be adapted for the grinding,

of workpieces having very varied shapes.

1 claim:

1. A device for grinding down a sizeable quantity of metal or similar material which is concentrated over a small area on a metal casting l said quantity of metal being disposed disymmetrically with respect to a given axis 16) of the workpiece (ll the device comprising:

agrinding wheel (3) mounted for rotation about its axis,

a workpiece support (4) for supporting said workpiece l) for rotation about said given axis (16) and parallel to the axis of the grinding wheel,

an element (14) for rotating said workpiece about said given axis and a second element (6) for moving said support (4) and said workpiece (1) towards and away from said grinding wheel, said second element (6) comprising a jack (6), one end (7) of which is stationary with respect to the workpiece and the other end (8) of which is integral with an arm (9), said arm (9) resting at one end on a stationary point (5) and resting on its other end on a shaft (11) disposed in the plane formed by the axis of the jack (6) and said arm, and said device includes means (10) for adjusting the position of the bearing point of the arm (9) on said shaft (11).

2. A device according to claim 1, characterized in that the means for regulating the position of the bearing point of the arm on the shaft consist of threading provided in the latter, a tapped ring (10) integral with the arm and screwed into the threading of the shaft and means (12,13) for rotating the shaft about its axis.

3. A device according to claim 1, wherein said support 4 is pivotable about a stationary axis and the stationary point (5) of the arm (9) is coincident with the stationary axis of the support.

4. A device according to claim 1, characterized in that the jack (6) is pneumatic.

5. A device according to claim 1, wherein said workpiece 1) is mounted on said support (4) for rotation about said given axis (16) and said device is further characterized by an element (14) for rotating said workpiece (1) about said given axis (16) into contact with said grinding wheel (3), said element comprising a second jack (14).

6. A device according to claim 5, characterized in that the jack (14) for rotating the workpiece in contact with the grinder comprises means for regulating the rate of rotation. 

1. A device for grinding down a sizeable quantity of metal or similar material which is concentrated over a small area on a metal casting (1), said quantity of metal being disposed disymmetrically with respect to a given axis (16) of the workpiece (11), the device comprising: a grinding wheel (3) mounted for rotation about its axis, a workpiece support (4) for supporting said workpiece (1) for rotation about said given axis (16) and parallel to the axis of the grinding wheel, an element (14) for rotating said workpiece about said given axis and a second element (6) for moving said support (4) and said workpiece (1) towards and away from said grinding wheel, said second element (6) comprising a jack (6), one end (7) of which is stationary with respect to the workpiece and the other end (8) of which is integral with an arm (9), said arm (9) resting at one end on a stationary point (5) and resting on its other end on a shaft (11) disposed in the plane formed by the axis of the jack (6) and said arm, and said device includes means (10) for adjusting the position of the bearing point of the arm (9) on said shaft (11).
 2. A device according to claim 1, characterized in that the means for regulating the position of the bearing point of the arm on the shaft consist of threading provided in the latter, a tapped ring (10) integral with the arm and screwed into the threading of the shaft and means (12,13) for rotating the shaft about its axis.
 3. A device according to claim 1, wherein said support 4 is pivotable about a stationary axis and the stationary point (5) of the arm (9) is coincident with the stationary axis of the support.
 4. A device according to claim 1, characterized in that the jack (6) is pneumatic.
 5. A device according to claim 1, wherein said workpiece (1) is mounted on said support (4) for rotation about said given axis (16) and said device is further characterized by an element (14) for rotating said workpiece (1) about said given axis (16) into contact with said grinding wheel (3), said element comprising a second jack (14).
 6. A device according to claim 5, characterized in that the jack (14) for rotating the workpiece in contact with the grinder comprises means for regulating the rate of rotation. 